Channel 4 Action News' Marcie Cipriani reported that police have information and evidence which leads them to believe the young Mount Washington woman was killed and has been buried.

The new search also involved ATVs and dogs in a wooded area behind the airport in West Mifflin. Kail's mother, Christine Didiano, of Brookline, joined police at their mobile command center and made a public plea for tips as she displayed a baby picture of her daughter.

"If Alivia's where they feel that she is, I just want to get her back and I'm looking forward to moving on," Didiano said. "There's still time and an opportunity that I want to reach out and say that someone or more that do know and have been very frightened, and it's very understandable ... During this time would be the very best time for a truth of somewhat to come out anonymously."

Some bones were found during Thursday's search. If they are determined to be human, police said they will be taken to a lab for DNA analysis. One has already been sent to the lab because a forensic pathologist wasn't sure if it was a human bone or an animal bone.

When Kail went missing in March 2011, it was reported to police by her brother, who told them that he last saw her at his West Mifflin home with her boyfriend. He told them that Kail said she was going to Florida with her boyfriend, but there was no proof that she ever made the trip.

Alex Lorenzi, described back then as Kail's boyfriend, was questioned by police and jailed for several weeks on unrelated drug charges, but he was never charged in connection with the woman's disappearance.

On Thursday, police said they were led to the airport by evidence that was collected at the time of Kail's disappearance, along with recent evidence after many interviews with people who they believe are connected to the case. They think more than one person could be responsible for her death.

"It's been very difficult on my life as far as normal things, every day, working, trying to do that, and the struggle and the chain wrapped around me," Didiano said. "I don't want the chain any more. The chain needs to come off of me, and that's going to happen when Alivia is found, so then at least I can continue to fight for her, for the crime, and then settle it, and then myself and my children can go ahead and live and get back to normal, because nothing's been normal."

In photos: The disappearance of Alivia Kail

1 of 18

Alivia Kail

Alivia Kail went missing at age 19 in March 2011. She was supposed to be going to Florida with a boyfriend.